Childhood overweight in the U.S. has reached epidemic proportions, which some researchers partly attribute to advertising by the food industry. The World Health Organization and the Institute of Medicine have proposed banning or limiting such advertising as part of a strategy to prevent childhood overweight, but both organizations acknowledge that the scientific basis for their recommendations is far from complete. The broad, long-term objective of this R21 Exploratory/Developmental Research Grant application is to use the tools of economics to advance our knowledge about the impact of advertising on youths' decisions that lead to energy imbalance and overweight; specifically, decisions about the consumption of fast food, soft drinks, candy, and sweetened breakfast cereals. Our specific aims are to estimate two-part econometric models of the impact of advertisements on: 1) youths' visits to specific fast food establishments, and youth consumption of specific brands of: 2) soft drinks; 3) sweetened breakfast cereals; and 4) candy. We will also 5) measure the fraction of variance in youth consumption decisions that is explained by advertising and 6) test whether the impact of advertising differs by the demographic characteristics of youth. Finally, we will 7) test whether food advertising steals market share from rival brands or increases consumption for all brands in the product class. The proposed research offers several advantages. We use a nationally-representative sample of 21,000 youths, larger than any previous study, which allows us to measure more accurately than ever before the relationship between advertising and child consumption and draw inferences about this relationship for all American youth. These unique data contain information on when youth watched television, which magazines they read, and their consumption of specific brands of food. To these data we merge rich data on the advertisements that appeared while they watched television and in the magazines they read. Together these data allow us to calculate a precise measure of the advertisements to which each youth was exposed. This will allow us to better estimate how food advertising impacts youth consumption. [unreadable] [unreadable]